Apparatus and method for performing an endoscopic mucosal resection

ABSTRACT

A surgical device including an elongated shaft having a distal end and a proximal end, an arm pivotally connected to the distal end and moveable through a dissection plane, and a cutting element disposed on the arm and adapted to move from an un-deployed configuration to a deployed configuration, wherein the cutting element is generally aligned with the dissection plane when in the un-deployed configuration and at least partially transverse with respect to the dissection plane when in the deployed configuration.

FIELD OF THE INVENTION

The present application relates to medical devices and methods and, moreparticularly, to medical devices and methods for performing resectionprocedures within the gastrointestinal and esophageal passages of thehuman body.

BACKGROUND OF THE INVENTION

Gastric cancers in the human body often stem from precursor lesions andpolyps that develop into superficial tumors or other growths. Suchlesions and growths typically begin in the mucosal layer of thegastrointestinal tract (e.g., the mucosa of the colon) and, as thecancer develops, may spread to the submucosal layer and beyond.Therefore, many physicians agree that successful cancer treatment andprevention typically requires the identification and removal of suspecttissue from the gastrointestinal tract.

Accordingly, physicians may collect samples of tissue from thegastrointestinal tract (e.g., samples of the mucosa) and test the sampletissue for the presence of cancerous cells. The tissue sampling may bepurely prophylactic or may be conducted in response to symptomsindicative of cancer. When cancerous lesions or the like are detected,curative treatments often require complete resection of the suspecttissue.

Various techniques have been developed for removing tissue from thewalls of the gastrointestinal tract. Such techniques commonly employ anendoscope that enters the body through a natural orifice (e.g., theanus) and, therefore, often are referred to as endoscopic mucosalresection (“EMR”) techniques.

Prior art EMR techniques typically include a “lift-and-cut” procedure,wherein a snare and forceps is used to grasp and lift the lesion whilethe physician cuts around the lesion. The cut typically is made throughthe mucosa and submucosa, taking particular caution not to penetrate themuscularis. However, such techniques have presented severaldisadvantages, including the difficulty associated with removing theentire suspect region and the risk of penetrating the muscularis duringcutting.

Accordingly, there is a need for an improved apparatus and method forperforming resection procedures within the gastrointestinal andesophageal passages of the human body.

SUMMARY OF THE INVENTION

In one aspect, a surgical device is provided and includes an elongatedshaft having a distal end and a proximal end, an arm pivotally connectedto the distal end and moveable through a dissection plane, and a cuttingelement disposed on the arm and adapted to move from an un-deployedconfiguration to a deployed configuration, wherein the cutting elementis generally aligned with the dissection plane when in the un-deployedconfiguration and at least partially transverse with respect to thedissection plane when in the deployed configuration.

In another aspect, a surgical device is provided and includes anelongated shaft having a distal end and a proximal end, at least twoarms connected to the distal end and moveable relative to each otherthrough a dissection plane, and a cutting element disposed on at leastone of the arms, the cutting element being adapted to move from anun-deployed configuration to a deployed configuration, wherein thecutting element is generally aligned with the dissection plane when inthe un-deployed configuration and at least partially transverse withrespect to the dissection plane when in the deployed configuration.

In another aspect, a method for resecting diseased tissue from an organof a patient is provided and includes the steps of positioning a devicehaving at least one arm between a second layer and a third layer of theorgan, moving the arm through the dissection plane between the secondand third layers to bluntly dissect the second layer from the thirdlayer, and deploying a cutting element from the arm, wherein the cuttingelement is deployed toward the first layer and away from the thirdlayer.

Other aspects of the disclosed apparatus and methods will becomeapparent from the following description, the accompanying drawings andthe appended claims.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a perspective view of one aspect of the disclosed apparatusfor performing an EMR procedure;

FIG. 2 is a perspective view of the apparatus of FIG. 1 in a secondconfiguration;

FIG. 3 is a perspective view of the apparatus of FIG. 1, wherein thecutting elements are in a deployed position;

FIG. 4 is a perspective view of the apparatus of FIG. 3 in the secondconfiguration;

FIG. 5 is a perspective view of an alternative aspect of the disclosedapparatus for performing an EMR procedure;

FIG. 6 is a perspective view of the apparatus of FIG. 5 in a secondconfiguration;

FIG. 7 is a perspective view of the apparatus of FIG. 6, wherein thecutting elements are in a partially deployed position;

FIG. 8 is a perspective view of the apparatus of FIG. 6, wherein thecutting elements are in a fully deployed position;

FIG. 9 is a perspective view of the apparatus of FIG. 8 in the secondconfiguration;

FIG. 10A is an elevational view, partially in section, of a firstalternative aspect of a cutting element;

FIG. 10B is an elevational view, partially in section, of the cuttingelement of FIG. 10A in a deployed position;

FIG. 11A is an elevational view of a second alternative aspect of acutting element;

FIG. 11B is an elevational view of the cutting element of FIG. 11A in adeployed position;

FIG. 12A is an elevational view, partially in section, of a thirdalternative aspect of a cutting element;

FIG. 12B is an elevational view, partially in section, of the cuttingelement of FIG. 12A in a deployed position;

FIG. 13 is cross-sectional view of a gastrointestinal wall of a humanpatient;

FIG. 14 is a cross-sectional view of the gastrointestinal wall of FIG.13 according to an aspect of the disclosed method for performing an EMRprocedure;

FIG. 15 is a cross-sectional view of the gastrointestinal wall of FIG.14 according to an aspect of the disclosed method for performing an EMRprocedure;

FIG. 16 is a top plan view, partially in section, of thegastrointestinal wall of FIG. 15, wherein the apparatus of FIG. 6 isinserted through the incision shown in FIG. 15 according to an aspect ofthe disclosed method for performing an EMR procedure;

FIGS. 17 and 18 are cross-sectional views of the gastrointestinal wallof FIG. 15, wherein the apparatus of FIG. 5 is performing a bluntdissection procedure according to an aspect of the disclosed method forperforming an EMR procedure;

FIG. 19 is a cross-sectional view of the gastrointestinal wall of FIG.18 after deployment of cutting elements according to an aspect of thedisclosed method for performing an EMR procedure;

FIG. 20 a cross-sectional view of the gastrointestinal wall of FIG. 19depicting a resection of suspect tissue according to an aspect of thedisclosed method for performing an EMR procedure; and

FIG. 21 is top plan view, partially in section, of the gastrointestinalwall of FIG. 20.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIGS. 1-4, a first aspect of an improved EMR device,generally designated 100, may include a dissection/actuation assembly102 disposed on the distal end 104 of an elongated shaft 106. Theassembly 102 and shaft 106 may be sized and shaped to be receivedthrough a natural orifice of the human body (not shown). The shaft 106may be flexible and may have a length sufficient to navigate the humangastrointestinal tract during an endoscopic procedure.

The assembly 102 may include a head 108, a first moveable arm 110, asecond moveable arm 112, a linkage assembly 114 and an actuation link orcable 116. The linkage assembly 114 may be comprised of four pivotallyconnected links 126 and may be disposed within the head 108. Theactuation cable 116 may extend through the elongated shaft 106 such thatit is accessible by a user.

The linkage assembly 114 may include a distal end 118 and a proximal end120, wherein the distal end 118 may be connected to the first and secondarms 110, 112 at a first pivot point 122 and the proximal end 120 may beconnected to the actuation cable 116 at a second pivot point 124.Additionally, the links 126 of the linkage assembly 114 may be connectedat third and fourth pivot points 128, 130.

Manipulation of the cable 116 in the direction shown by arrow A mayachieve a compression of the linkage assembly 114 (i.e., the links 126may extend radially with respect to the longitudinal axis of the device100) and a corresponding pivot of the arms 110, 112 about pivot point122 to an open configuration, as shown in FIGS. 1 and 3. Referring toFIGS. 2 and 4, manipulation of the cable 116 in the direction shown byarrow B may achieve expansion of the linkage assembly 114 (i.e., thelinks 126 may extend axially with respect to the longitudinal axis ofthe device 100) and a corresponding pivot of the arms 110, 112 aboutpivot point 122 to a closed configuration.

Accordingly, by manipulating the cable 116, a user can move the arms110, 112 of the device 100 to an open position, a closed position orvarious positions therebetween in a scissor-like action. Thus, when thedevice 100 is positioned between layers of tissue, a user may bluntlydissect the tissue and separate the layers by urging the device throughthe tissue while using the scissor-like action described herein.

At this point, those skilled in the art will appreciate that the device100 may be provided with various arms and/or linkage assemblies suchthat the arms move and/or separate relative to each other in variousways. For example, a linkage assembly may be provided such that thecorresponding arms remain generally parallel while opening and closing.

Referring again to FIGS. 1-4, each arm 110, 112 may be provided with adeployable cutting element assembly 132 for deploying a cutting element134. The cutting element 134 may be a monopolar knife, an electrocauteryknife or other electrically activated cutting device. Alternatively, thecutting element 134 may be a mechanical cutting device such as a scalpelor the like.

The cutting element assembly 132 may advance the cutting element 134from a first (i.e., not deployed) configuration, as shown in FIGS. 1 and2, to a second (i.e., deployed) configuration, as shown in FIGS. 3 and4. In one aspect, the cutting element 134 may be deployed in a generallyradial direction with respect to the associated arm 110, 112. In anotheraspect, the cutting element 134 may be deployed in a direction that isgenerally perpendicular or at least partially transverse with respect tothe plane of movement of the arms 110, 112.

In one aspect, in addition to the cutting element 134, the cuttingelement assembly 132 may include an actuation bar 136 connected to anactuation link or cable 138, wherein manipulation of the actuation cable138 may facilitate deployment of the cutting element 134. The actuationcable 138 may extend through the shaft 106 such that it may bemanipulated by a user at the proximal end of the shaft 106. In oneaspect, the actuation cable 138 may be connected to a power source andmay provide monopolar electrical energy to the cutting element 134.

The cutting element 134 may include a cutting tip 146 and a pivot end148, wherein the pivot end 148 of the cutting element 134 is pivotallyconnected to the associated arm 110, 112 at a pivot point 150. Theactuation bar 136 may include a distal end 140 and a proximal end 142,wherein the distal end 140 may be pivotally connected to the cuttingelement 134 at a pivot point 144. The proximal end 142 of the actuationbar 136 may be connected to the actuation cable 138 and may include apin 152 slidably engaged with a camming track 154 in the associated arm110, 112.

Accordingly, manipulation (e.g., pushing, pulling, twisting or the like)of the actuation cable 138 may urge the actuation bar 136 in thedirection shown by arrow C, thereby urging the cutting element 134 tothe deployed position. Furthermore, reversing the manipulation mayretract the cutting element 134 into the associated arm 110, 112 of thedevice 100.

Referring to FIGS. 5-9, an alternative aspect of the improved EMRdevice, generally designated 200, may include a dissection/actuationassembly 202 disposed on the distal end 204 of an elongated shaft 206.The assembly 202 may be manipulated by user controls (not shown)disposed at the proximal end (not shown) of the shaft 206.

The assembly 202 may include first and second moveable arms 208, 210pivotally connected to a head 212 at a pivot point 214. A linkageassembly 216 and associated actuation cable 218 may be connected to thearms 208, 210 to allow a user to move the first arm relative to thesecond arm by manipulating the actuation cable 218 (e.g., by way of theuser controls). For example, the arms 208, 210 may move in ascissor-like fashion through a dissection plane, as shown in FIGS. 5 and6.

Each arm 208, 210 may be comprised of three pivotally connected links: aproximal link 220, a middle link 222 and a distal or tip link 224. Theproximal link 220 of arm 208 may be pivotally connected to the proximallink 220 of arm 210 at the pivot point 214. The middle link 222 of eacharm 208, 210 may include a distal portion 226 pivotally connected to thetip link 224 at pivot point 228 and a proximal portion 230 pivotallyconnected to the proximal link 220 at pivot point 232.

The tip link 224 of each arm 208, 210 may include a cutting element 234thereon. The cutting element 234 may be a monopolar knife, anelectrocautery knife or other electrically activated cutting device.Alternatively the cutting element 234 may be a mechanical cutting devicesuch as a scalpel or the like. Optionally, the cutting element 234 maybe retractable within an associated arm 208, 210 such that the cuttingelements 234 may be deployed only when needed.

An actuating wire or cable 236 may be connected to the tip link 224 andmay extend through the middle and proximal links 222, 220, through thehead 212 and shaft 206 and may be presented for manipulation at theproximal end of the shaft 206 (e.g., at the user controls). Therefore, aforce (e.g., pulling, pushing, twisting or the like) may be applied tothe cable 236 to urge the links 126 of the arms 208, 210 from theposition shown in FIG. 6, to the partially deployed position shown inFIG. 7 and, finally, to the fully deployed position shown in FIG. 8 (orvarious positions therebetween).

Thus, when the arms 208, 210 are in the fully deployed position, thecutting elements 234 may be positioned generally perpendicular or atleast partially transverse with respect to the plane of movement (i.e.,the dissection plane) ofthe arms 208, 210.

In one aspect, the actuation cable 236 may be electrically conductiveand may electrically connect the cutting element 234 to a power source(not shown) (e.g., a source of monopolar electrical energy), therebyserving as an actuating element for deploying the cutting element 234and as a conductor for supplying electrical energy to the cuttingelement 234.

At this point, those skilled in the art will appreciate that the EMRdevices disclosed herein allow a user to control the relative movementof two or more arms in an opening-and-closing-type action generallythrough a blunt dissection plane and deploy cutting elements in adirection that is generally perpendicular or at least partiallytransverse to the blunt dissection plane. Furthermore, those skilled inthe art will appreciate that various deployable cutting elementassemblies may be used with the devices described herein.

Referring to FIGS. 10A and 10B, a first alternative aspect of adeployable cutting element assembly, generally designated 300, mayinclude a wire 302 extending through an internal channel 304 of anassociated arm 306 (e.g., arm 110) of the device (e.g., device 100). Adistal portion 308 of the wire 302 may exit the internal channel 304 byway of an opening 310 in the arm 306. The proximal portion 312 of thewire 302 may extend through the arm 306 and the associated device suchthat it may be externalized and/or manipulated by a user (e.g., by wayof user controls (not shown)) and connected to a source of monopolarelectrical energy (not shown).

The distal most tip 314 of the wire 302 may be fixedly connected to thearm 306 such that, when the wire 302 is urged in the direction shown byarrow D, the distal portion 308 of the wire 302 may extend radially withrespect to the associated arm 306 and may form a cutting tip 316, asshown in FIG. 10B.

Thus, the cutting element may be deployed by urging the wire 302 in thedirection of arrow D and withdrawn by urging the wire 302 in thedirection shown by arrow E. The cutting tip 316 may serve as a monopolarknife when electrical energy is supplied to the wire 302.

Referring to FIGS. 11A and 11B, a second alternative aspect of adeployable cutting element assembly, generally designated 400, mayinclude a first link 402, a second, distal link 404, a third link 406and a cutting element 408. The cutting element 408 may be fixedlyconnected to the distal link 404.

The cutting element 408 may be an electrode of an electrically actuatedcutting device and may be electrically connected to an electrical powersupply (not shown). Alternatively, the cutting element 408 may be amechanical cutting device, such as a scalpel or the like.

The links 402, 404, 406 may be arranged such that movement of the firstlink 402 relative to the third link 406 causes the cutting element tomove from the un-deployed position shown in FIG. 11A to the deployedposition shown in FIG. 11B. In one aspect, the first link 402 may beconnected to the second link 404 by a first hinge 410 and the third link406 may be connected to the second link 404 by a second hinge 412. Firstand/or second hinges 410, 412 may be living hinges, pivot points or thelike.

Thus, movement of the third link 406 relative to the first link 402 inthe direction shown by arrow F may urge the cutting element 408 to thedeployed position.

Referring to FIGS. 12A and 12B, a third alternative aspect of adeployable cutting element assembly, generally designated 500, mayinclude a first electrically insulating sheath 502, a secondelectrically insulating sheath 504, two flexible coils 506, 508 andacutting element 510. The first flexible coil 506 may extend through thefirst sheath 502 and the second flexible coil 508 may extend through thesecond sheath 504. The distal portions 512 of the flexible coils 506,508 may be connected to each other to form a tip 514 and the cuttingelement 510 may be fixedly connected to the tip 514.

The cutting element 510 may be an electrode of an electrically actuatedcutting device and may be electrically connected to an electrical powersupply (not shown). For example, at least one of the flexible coils 506,508 may serve as a conductor to electrically couple the cutting element510 to the electrical power supply. Alternatively, the cutting element408 may be a mechanical cutting device, such as a scalpel or the like.

Accordingly, the cutting element 510 may be deployed from the firstconfiguration shown in FIG. 12A to the second configuration shown inFIG. 12B by urging the first coil 506 in the direction shown by arrow Gand/or the second coil 508 in the direction shown by arrow H.

At this point, those skilled in the art will appreciate that assemblies300, 400 and/or 500 may serve as the arms of the EMR devices disclosedherein (e.g., arms 110, 112 or arms 208, 210). Alternatively, theassemblies 300, 400 and/or 500 may be separate from and/or may bedisposed within the arms of the EMR devices disclosed herein.

Referring to FIGS. 13-21, the apparatus and methods described herein maybe employed to resect a lesion 600 or other suspect tissue or growthfrom the intestinal wall 602 of a patient during an endoscopicprocedure. However, those skilled in the art will appreciate that theapparatus and methods described herein may be used to perform variousother medical procedures, including removing suspect tissue from theesophageal wall or other tissue or organs of the body.

The intestinal wall 602 typically is comprised of four layers: themucosa 604, the submucosa 606, the muscularis 608 and a thin layer ofserosa 610. Successful treatment typically requires the resection of thelesion 600 as well the adjacent portions of the mucosa 604 and submucosa606 without penetrating the muscularis 608. Therefore, the apparatus andmethods described herein allow a physician to separate the mucosa 604and submucosa 606 adjacent to the lesion 600 (i.e., the target tissue612) and resect the target tissue 612 without penetrating the muscularis608.

Referring to FIGS. 13 and 14, a physician optionally may facilitate orinitiate the separation of the mucosa 604 and submucosa 606 from themuscularis 608 by injecting a fluid 614 into the submucosa 606 with an.injection needle 616 or the like. The fluid 614 may be a liquid, such asa sterile saline solution, or a gas, such as carbon dioxide gas. Asshown in FIG. 14, the fluid 614 may form a cushion 618 in the submucosa606 and may elevate the target tissue 612, thereby facilitating theinsertion of an EMR device.

In one aspect, the injection needle 616 may be mounted on or otherwiseconnected to an arm of the EMR device. In another aspect, the injectionneedle 616 may be retractable within an arm of the EMR device.

Referring to FIGS. 15 and 16, a physician may form an initial incision620 through the mucosa 604 and submucosa 606 into the target tissue 612,thereby providing access to the region between the submucosa 606 and themuscularis 608 beneath the target tissue 612. In one aspect, theincision 620 may be made with a knife or scalpel using any availablesurgical tools or techniques. In another aspect, the incision 620 may bemade using an EMR device disclosed herein.

Referring again to FIGS. 15 and 16, and referring to device 200 as anexample only, the device 200 may be configured in the un-deployedposition (see FIG. 6) and the cutting elements 234 may be actuated with,for example, monopolar electrical energy. The incision 620 may be formedby applying the actuated cutting elements 234 to the tissue such thatthe cutting elements 234 penetrate the mucosa 604 and submucosa 606 andprovide access to the region between the submucosa 606 and themuscularis 608. The size of the incision 620 may be increased bydisplacing the arms 208, 210 of the device 200 while the cuttingelements 234 are actuated.

At this point, those skilled in the art will appreciate that the initialincision 620 may be formed using the cutting elements described above(i.e., the cutting elements used to resect suspect tissue). However,those skilled in the art will also appreciate that the EMR devicesdisclosed herein may have a separate and/or independent cutting systemfor creating the initial incision 620.

The device 200 may be inserted through the initial incision 620 andpositioned between the submucosa 606 and the muscularis 608. As shown inFIGS. 17 and 18, using the scissor-like action of the arms 208, 210described herein, the device 200 may advanced beneath the target tissue612 to separate or bluntly dissect the submucosa 606 from the muscularis608 and, if necessary, disconnect any connective tissue therebetween.

Once the target tissue 612 has been separated from the muscularis 608,the cutting elements 234 may be configured to the deployed position suchthat the cutting elements 234 are at least partially transverse withrespect to the blunt dissection plane, as shown in FIG. 19. In oneaspect, the cutting elements 234 may be deployed such that they cut thesubmucosa 606 and mucosa 604 above the device 200 (i.e., away from themuscularis 608). In another aspect, the cutting elements 234 may bedeployed such that they are directed towards the center of the lumenformed by the intestinal wall 602.

Referring to FIGS. 20 and 21, once the cutting elements 234 are deployedand actuated (e.g., with monopolar electrical energy), the target tissue612 may be resected by advancing and/or retracting the device 200through the region between the muscularis 608 and the submucosa 606,while opening and closing the arms 208, 210 in the scissor-like actiondescribe herein. The resulting cut 622 may free the target tissue 612from the intestinal wall 602 such that it may be removed from thegastrointestinal tract using, for example, a snare, graspers or thelike.

Thus, the apparatus and methods disclosed herein allow a physician toresect suspect tissue from the intestinal wall 602 by bluntly dissectingthe submucosal layer 606 from the muscularis 608 adjacent to the targettissue 612 and, working with cutting elements (e.g., cutting elements234) that are directed away from the plane of the muscularis 608,cutting around the target tissue 612.

Although various aspects of the disclosed apparatus and methods havebeen shown and described, modifications may occur to those skilled inthe art upon reading the specification. The present application includessuch modifications and is limited only by the scope of the claims.

1. A surgical device comprising: an elongated shaft having a distal endand a proximal end; a first arm pivotally connected to said distal endand moveable through a dissection plane; and a cutting element disposedon said first arm and adapted to move from an un-deployed configurationto a deployed configuration, wherein said cutting element is generallyaligned with said dissection plane when in said un-deployedconfiguration and at least partially transverse with respect to saiddissection plane when in said deployed configuration.
 2. The device ofclaim 1 further comprising a second arm pivotally connected to saiddistal end and moveable relative to said first arm through saiddissection plane.
 3. The device of claim 2 wherein said second arm movesrelative to said first arm in a scissor-like action.
 4. The device ofclaim 2 wherein said second arm remains generally parallel with respectto said first arm when said second arm moves relative to said first arm.5. The device of claim 2 wherein said second arm includes a secondcutting element adapted to move from said un-deployed configuration tosaid deployed configuration, wherein said second cutting element isgenerally aligned with said dissection plane when in said un-deployedconfiguration and at least partially transverse with respect to saiddissection plane when in said deployed configuration.
 6. The device ofclaim 1 further comprising a first actuation cable connected to saidfirst arm and extending through said elongated shaft, whereinmanipulation of said first actuation cable facilitates a correspondingmovement of said first arm.
 7. The device of claim 1 further comprisinga second actuation cable connected to said cutting element and extendingthrough said elongated shaft, wherein manipulation of said secondactuation cable facilitates deployment of said cutting element.
 8. Thedevice of claim 7 wherein said cutting element is a monopolar knife andsaid second actuation cable electrically connects said monopolar knifeto a source of monopolar electrical energy.
 9. The device of claim 1wherein said cutting element includes an electrically activated cuttingdevice.
 10. The device of claim 9 wherein said cutting element iselectrically insulated from said first arm.
 11. The device of claim 1wherein said cutting element is generally perpendicular to saiddissection plane when in said deployed configuration.
 12. The device ofclaim 1 wherein, when said first arm is disposed between a mucosal layerand a muscularis layer of a human organ, said dissection plane of saidfirst arm is generally aligned with said muscularis layer and saidcutting element is directed generally away from said muscularis layerwhen in said deployed configuration.
 13. A surgical device comprising:an elongated shaft having a distal end and a proximal end; at least twoarms connected to said distal end and moveable relative to each otherthrough a dissection plane; and a cutting element disposed on at leastone of said arms, said cutting element being adapted to move from anun-deployed configuration to a deployed configuration, wherein saidcutting element is generally aligned with said dissection plane when insaid un-deployed configuration and at least partially transverse withrespect to said dissection plane when in said deployed configuration.14. The device of claim 13 further comprising a first actuation cableconnected to said arms and extending through said elongated shaft,wherein manipulation of said first actuation cable facilitates acorresponding movement of said arms.
 15. The device of claim 13 furthercomprising a second actuation cable connected to said cutting elementand extending through said elongated shaft, wherein manipulation of saidsecond actuation cable facilitates corresponding movement of saidcutting element to said deployed configuration.
 16. The device of claim15 wherein said cutting element is a monopolar knife and said secondactuation cable electrically connects said monopolar knife to a sourceof monopolar electrical energy.
 17. The device of claim 15 wherein saidcutting element is a monopolar knife and said second actuation cable iselectrically isolated from said monopolar knife.
 18. The device of claim13 wherein said cutting element includes an electrically activatedcutting device.
 19. The device of claim 18 wherein said electricallyactivated cutting device includes a monopolar knife.
 20. The device ofclaim 13 wherein said cutting element is generally perpendicular to saiddissection plane when in said deployed configuration.
 21. The device ofclaim 13 wherein, when said arms are disposed between a mucosal layerand a muscularis layer of a human organ, said dissection plane of saidarms is generally aligned with said muscularis layer and said cuttingelement is directed generally away from said muscularis layer when insaid deployed configuration.
 22. A method for resecting target tissuefrom an organ of a patient, wherein said organ is formed from at leasttwo layers, said method comprising the steps of: positioning a devicehaving at least one arm between a first layer and a second layer of saidorgan; moving said arm through a dissection plane between said firstlayer and said second layer to bluntly dissect said first layer fromsaid second layer; and deploying a cutting element from said arm,wherein said cutting element is deployed toward said first layer andaway from said second layer.
 23. The method of claim 22 furthercomprising the step of cutting around said target tissue by moving saidarm relative to said dissection plane while said cutting element isdeployed.
 24. The method of claim 23 wherein said cutting element is amonopolar knife and said cutting step includes supplying monopolarelectrical energy to said monopolar knife.
 25. The method of claim 22wherein said organ is a colon, said first layer is a submucosal layer ofsaid colon and said second layer is a muscularis layer of said colon.26. The method of claim 22 wherein said organ is at least one of a humanesophagus, a human stomach and a human gall bladder.
 27. The method ofclaim 23 wherein said device includes two arms, each of said armincluding at least one of said cutting elements.
 28. The method of claim27 wherein said cutting step includes varying a degree of separation ofa first one of said arms relative to a second one of said arms.